A belt reel for a seat belt retractor comprises a cylindrical spool for a belt webbing as well as at least one collar arranged at an axial end of the spool.
Typically, the belt reel is connected to a coiling spring which biases the belt reel in the winding direction of the belt webbing. Under normal operating circumstances the belt webbing can be freely withdrawn from the belt retractor against the force of the coiling spring, whereas when a webbing-sensitive or vehicle-sensitive locking mechanism is activated the belt reel is blocked so that the belt webbing cannot be withdrawn any further from the belt retractor. In this condition tensile forces in the belt webbing resulting from deceleration forces acting on a vehicle occupant in a possible collision are directed via the belt reel and the belt retractor into the vehicle. This is why the belt reel needs to be dimensioned such that it withstands the forces occurring in such a case under all circumstances. At the same time the intention is to dimension the belt reel as small as possible to enhance the capacity for receiving the belt webbing.
Belt reels are known hitherto from prior art which are either configured as a die-cast component or consist of a plastic-jacketed steel axle. Such designs are, however, a disadvantage both as regards their cost and their weight.
It is thus the object of the invention to provide a belt reel for a belt retractor which can be manufactured significantly cheaper and is less heavy.